Which of the following best describes valence electrons and their importance?

• A. Valence electrons are neutrons that affect the mass number but not chemical reactivity.
• B. Valence electrons are the outermost electrons of an atom and determine how the atom interacts and bonds with other atoms.
• C. Valence electrons are protons in the nucleus that determine the atomic number of an element.
• D. Valence electrons are the electrons found in the innermost shell and are not involved in chemical bonding.

Answer: (B)

Verified step by step guidance

1. Understand that valence electrons are the electrons located in the outermost shell (energy level) of an atom.
2. Recognize that these outermost electrons are the ones involved in chemical bonding and interactions with other atoms.
3. Note that valence electrons determine the chemical properties and reactivity of an element because they can be gained, lost, or shared during chemical reactions.
4. Distinguish valence electrons from protons (which are in the nucleus and define the atomic number) and neutrons (which affect mass but not chemical behavior).
5. Remember that electrons in inner shells (core electrons) generally do not participate in bonding, so valence electrons are key to understanding how atoms form molecules.